autonomic physiology

Question 1

What do beta 2 receptors generally do?

Answer 1

Relax smooth muscle.

Question 2

What affect does the sympathetic NS have on the eye?

Answer 2

Activation of B2 receptors on ciliary muscle around lens makes it relax so eye can focus far away. Activation of A1 receptors of radial muscle of iris to contract it and make the pupil larger.

Question 3

What affect does the parasympathetic NS have on the eye?

Answer 3

Activation of muscarinic receptors on ciliary muscle and sphincter muscle. Eye focuses close up and pupil is smaller.

Question 4

What affect does the sympathetic NS have on the heart?

Answer 4

Activation of B1 receptors on pacemaker cells and myocytes. Makes the heart beat faster and stronger.

Question 5

What affect does the parasympathetic NS have on the heart?

Answer 5

Activation of muscarinic receptors on pacemaker cells to decrease heart rate.

Question 6

What affect does the sympathetic NS have on the lungs?

Answer 6

Activation of B2 receptors in smooth muscle to dilate airways. (Salbutamol: B2 agonist that dilates the airways but does not affect the heart. Atenolol: B1 antagonist which decreases heart rate but does not affect the airways)

Question 7

What affect does the parasympathetic NS have on the lungs?

Answer 7

Activates muscarinic receptors to make smooth muscle contract and constricts airways.

Question 8

What affect does the sympathetic NS have on the blood vessels?

Answer 8

In some tissues, A1 receptors activated to constrict and in other tissues B2 activated to relax and increase blood flow.

Question 9

What affect does the parasympathetic NS have on the blood vessels?

Answer 9

No effect.

Question 10

What affect does the sympathetic NS have on the gut?

Answer 10

Activation of A/B receptors in the gut to decrease motility. Activation of A receptors in pancreas to inhibit enzyme secretion.

Question 11

What affect does the parasympathetic NS have on the gut?

Answer 11

Activation of muscarinic receptors on smooth muscle of gut and pancreas. Immodium?Inhibits ACh release.

Question 12

What affect does the sympathetic NS have on energy stores?

Answer 12

Activates A/B cells on liver cells (gluconeogenesis and glycogenolysis) and on fat cells (increases lipolysis).

Question 13

What affect does the parasympathetic NS have on energy stores?

Answer 13

No effect.

Question 14

What affect does the sympathetic NS have on the salivary glands?

Answer 14

Activates B receptors to stimulate a thick secretion rich in enzymes.

Question 15

What affect does the parasympathetic NS have on the salivary glands?

Answer 15

Activation of muscarinic receptors stimulates a profuse watery secretion.

Question 16

What affect does the sympathetic NS have on the bladder?

Answer 16

Activation of B2 on bladder wall to relax smooth muscle and reduce pressure. Activation of A1 on sphincter to contract smooth muscle and stop urination.

Question 17

What affect does the parasympathetic NS have on the bladder?

Answer 17

Activates muscarinic on bladder wall to contract and increase pressure. Also activates muscarinic on sphincter to relax smooth muscle and allow urination.

Question 18

What affect does the sympathetic NS have on the reproductive tract?

Answer 18

Activates A1 to contract smooth muscle of urethra and cause ejaculation.

Question 19

What affect does the parasympathetic NS have on the reproductive tract?

Answer 19

Activates muscarinic receptors of corpus cavernosum which relaxes smooth muscle and causes erection.

Question 20

Which 2 processes control all of these responses?

Answer 20

Autonomic reflexes (baroreceptors detect BP) and central control (hypothalamus).